This quadcopter is designed to be lightweight. It uses 16 mm carbon fibre tubes as motor arms. All other parts of the frame are 3D printed. I printed the parts in PLA, but maybe PETG or ABS is a better choice to make it more crash resistant. The motor cables are routed inside the carbon fibre tubes, making the quad look really clean. The quad uses 6 inch propellers and is slightly larger than a standard race-quad. The total flying weight is 630 grams and is has a flight time of about 7 minutes while cruising around at a comfortable pace.
The carbon fibre tubes I used are those: Hobbyking link
They are 16 mm outer diameter, 14 mm inner diameter and 330 mm long. I bought 2 of those and cut them in half to create four 165 mm long motor arms. The 3D printed parts are made to fit any tube with a 16 mm outer diameter. The motor mounts are firstly glued using CA glue to the carbon fibre tubes, then the tubes are glued to the base plate. The camera mount and rear mounting plate are screwed together using short M3 screws and nuts. The top plate is held in place using four 3D printed spacers. The holes in the spacers are slightly smaller than 3 mm, making it possible to thread M3 screws directly into the plastic.
The STL files for all the 3D printed parts are available for download here: 3DprintedQuadSTL.zip
Update 2017-07-28
Since this project was very successful, I have updated the design slightly to make the quadcopter more durable. I have also added versions of the motor mounts and base plate that works with 14 mm carbon fibre tubes. Now there is also motor mounts with integrated landing gears available.
updatede the following setup in this quadcopter:
- Motors: Racestar Racing Edition 2205 2300KV
- ESCs: Racestar 20A BLHELI_S OPTO
- Flight controller: BF3.1.5 Omnibus F4 V2 Flight Controller STM32 F405 MCU Integrated OSD Built-in 5V BEC Current Meter
- Battery: LiPo 3 cell 2200mAh
- FPV camera: 600TVL 2.8mm Lens 1/3″ Super Had II CCD Camera IR Sensitive for FPV Racing Drone PAL/NTSC
- Video transmitter: Eachine TX526 5.8G 40CH 25MW/200MW/600MW Switchable AV Wireless FPV Transmitter RP-SMA Female
- Video antennas: DYS FPV 5.8G Antenna 4dBi Mushroom Antenna RHCP TX RX SMA RP-SMA Male
This is the first quadcopter I have built using modern equipment. My RC receiver is connected to the flight controller using S-bus. It makes for a very clean installation with only one cable. But the biggest difference compared to older systems is probably that this flight controller uses a gyro chip that is connected to the microprocessor over SPI interface. this allows it to get updated data from the gyro at a rate of 8KHz. This in combination with good ESCs capable of the very fast Multishot interface makes the quadcopter extremely stable and at the same time also very responsive. I am running the “Betaflight” firmware in my flight controller, the stock PID settings seam to very stable, both in acro mode and horizon mode (stabilize mode).
The flight controller also has a highly customizable OSD (on screen display). It adds information about battery capacity, timers, altitude and other stuff to the video image before it is sent to the video transmitter.
